Determination of uranium in environmental matrices by chelation ion chromatography using a high performance substrate dynamically modified with 2,6-pyridinedicarboxylic acid

Abstract

Chelation ion chromatography, involving a high efficiency neutral polystyrene-divinylbenzene resin dynamically coated with 2,6-pyridinedicarboxylic acid, has been developed as a novel technique for the quantitative determination of uranium in complex matrices. An isocratic separation method, using an eluent consisting of 1M KNO3, 0.5M HNO3 and 0.1 mM 2,6-pyridinedicarboxylic acid, allowed the uranyl ion to elute away from matrix interferences in under ten minutes. Detection was achieved using an Arsenazo III post column reaction system. Good recoveries were obtained from spiked mineral water and sea water and the standard addition curves produced good linearity (r2>0.997) with a detection limit, calculated as twice baseline noise, of 20 μg L−1. The procedure was applied to the determination of trace uranium in standard reference water and sediment samples. The results obtained compared well with the certified values for uranium.